Phase I Environmental Site Assessment Schoolfield Placer and Third National Mill Site Dumont, Colorado 80436 June 5, 2019 Prepared By: Sundance Environmental Consultants, Inc. 11584 Wilson Circle, Parker, Colorado 80134 (303) 699-7870 Prepared For: Jason Smith Phase I Environmental Site Assessment Schoolfield Placer and Third National Mill Site, Stanley Road, Dumont, Colorado 1 SUMMARY The subject property consists of approximately 11 acres of land associated with historic mining claims, including hard rock mining, placer mining, and potentially milling operations. A railroad was historically present along the northern edge of the site. Most of the mining activities occurred in the late 1800s and early 1900s, although one mine area may still be in use. Several mine rock piles are visible on the subject property, and the toe of a mine rock pile that is still in use encroaches onto the Third National mill site portion of subject property. This pile displays rock fragments that are yellow or golden in color, and is not vegetated. The bulk of the property contains grasses and trees on mountainous land that steepens uphill toward the south. Several debris piles were noted on the subject property, mostly consisting of dead wood. Some rusty metal pipe and rusty wire rope were observed in one pile. Some limited building material such as wooden lattice had been dumped. Trash on the ground included metal cans, plastic bottles, empty burlap sacks, shot gun shell casings, old rubber hose, and a small piece of linoleum. No chemical containers or ground staining were observed on the subject property. This debris did not appear to contain any significant evidence of hazardous substances or petroleum products. A buried gas line and an overhead electric line are present along Stanley Road and the north edge of the property. No electrical transformers were noted. No utility services connecting to the subject property were observed. No water wells, septic tanks or leachfields were observed. No structures or foundations were observed at the subject property. Groundwater at the subject property is estimated to flow north toward Clear Creek, then eastward with the creek. The subject property is bordered to the north by Stanley Road and the Colorado Adventure Center, to the east and west by undeveloped land, and to the south by undeveloped mountain side and mine properties. Historic aerial photography beginning in 1938 was reviewed for evidence of past land use. Ground disturbance that was likely related to mining is present on many of the photographs, at various locations along the subject property. Topographic maps show that a railroad was present in 1912, and multiple mine adits are also shown subsequent maps, generally near the mine rock piles. A mine sheet from 1901 presents the locations of the mining claims in the area including those on the subject property. One environmental database record was discovered for the subject property. An “underground” mine record named Stanley Mine was issued to Equity Gold, Inc. in 1981. The area was approximately 9 acres, and the status is now listed as “revoked and terminated.” The location of this mine is mapped as being on the north edge of the subject property. Sundance did not observe any direct evidence of this mine during site reconnaissance. Additional database information from the Colorado Division of Mining, Sundance Environmental Consultants, Inc. 2 Phase I Environmental Site Assessment Schoolfield Placer and Third National Mill Site, Stanley Road, Dumont, Colorado Reclamation and Safety indicates that this 110(2) mine type includes hard rock/metal mining with limited impact operations. No other information was discovered for this mine, or the subject property parcels of Schoolfield Placer or Third National MS for this Phase I report. The site is located within the Central City/Clear Creek Superfund Site study area which encompasses 400 square miles, but the boundaries of the active Superfund site do not include the subject property. This Superfund Site is known to have contaminated stream water quality with acid mine drainage and wastes from historic mining tunnels and practices in the vicinity. This nearby Superfund site record does not directly affect the subject property, but does establish that there have been environmental concerns due to historic mining along Clear Creek. In the opinion of Sundance, the historic mining land use of this property is considered to be a Recognized Environmental Condition (REC). This includes historic mine records of a placer and mine site or mill site claim on the entire subject property, and the database record of the closed Stanley underground mine. In addition, the existing mine rock piles contain unknown concentrations of heavy metals. The subject property is zoned for mining and single-family residence. Future land use may include a residence, with possible expansion of development such as for cabins, an RV park, and a brewery. Sundance recommends soil testing in areas of existing mine rock piles, and other areas of future grading or development. While wide-spread heavy metals concentrations in soil are not expected, this should be documented prior to further development for residential land usage, vegetable gardens, over-lot grading or building of dirt roads. Groundwater contamination is not expected, but this should also be tested if a water supply well is anticipated for site development. Sundance Environmental Consultants, Inc. (Sundance) has performed a Phase I Environmental Site Assessment (ESA) in conformance with the scope and limitations of ASTM practice E 1527-13 of portions of the Schoolfield Placer and Third National Mill Site along Stanley Road near Dumont, Colorado (“the subject property”). Any exceptions to, or deletions from this practice, are described in the Deviations section of this report. This Phase I ESA has revealed evidence of recognized environmental conditions (RECs) in connection with the subject property, including: • Historic mine records on the subject property, and • Mine rock piles and surface soils of unknown heavy metals concentrations in areas of anticipated residential land use. No historic RECs or controlled RECs were identified. Additional environmental assessment is recommended. Sundance Environmental Consultants, Inc. 3 Phase I Environmental Site Assessment Schoolfield Placer and Third National Mill Site, Stanley Road, Dumont, Colorado TABLE OF CONTENTS 1 SUMMARY.................................................................................................................................. 2 TABLE OF CONTENTS ............................................................................................................... 4 2 INTRODUCTION ...................................................................................................................... 6 2.1 PURPOSE ........................................................................................................................................ 6 2.2 DETAILED SCOPE-OF-SERVICES ............................................................................................ 6 2.3 SIGNIFICANT ASSUMPTIONS .................................................................................................... 6 2.4 LIMITATIONS AND EXCEPTIONS ............................................................................................. 7 2.5 SPECIAL TERMS AND CONDITIONS ....................................................................................... 7 2.6 USER RELIANCE ........................................................................................................................... 8 3 SITE DESCRIPTION ................................................................................................................. 9 3.1 LOCATION AND LEGAL DESCRIPTION .................................................................................. 9 3.2 SITE AND VICINITY GENERAL CHARACTERISTICS ........................................................... 9 3.3 CURRENT USE OF THE PROPERTY ...................................................................................... 10 3.4 DESCRIPTION OF STRUCTURES, ROADS, OTHER IMPROVEMENTS ON THE SITE10 3.5 CURRENT USES OF ADJOINING PROPERTIES ................................................................. 10 4 USER PROVIDED INFORMATION ...................................................................................... 11 4.1 TITLE RECORDS ......................................................................................................................... 11 4.2 ENVIRONMENTAL LIENS OR ACTIVITY AND USE LIMITATIONS .................................. 11 4.3 SPECIALIZED KNOWLEDGE .................................................................................................... 11 4.4 COMMONLY KNOWN OR REASONABLY ASCERTAINABLE INFORMATION ............. 11 4.5 VALUATION REDUCTION FOR ENVIRONMENTAL ISSUES ............................................ 11 4.6 OWNER, PROPERTY MANAGER, AND OCCUPANT INFORMATION ............................. 11 4.7 REASON FOR PERFORMING PHASE I ESA ........................................................................ 11 4.8 OTHER ........................................................................................................................................... 11 5 RECORDS REVIEW ................................................................................................................ 12 5.1 STANDARD ENVIRONMENTAL RECORD SOURCES AND RESULTS........................... 12 5.2 ADDITIONAL